compressing code?

I am far off this point, but lets say you wanted to make a huge application. Is it worth it to cut out any black rows and get as many things on one line as possible? I know it will be tough to read the code, but it can subtract sometimes more then 10% off the programs size. I made a simple 100KB program and i noticed a tiny little pause (hardly noticeable unless looking for it). I then took out all the empty rows in my code and arranged a few lines that could be fit on one line(instead of two or three). My program was then 70KB and I noticed no pause. What's everybodies insite on this? Am I just being a stupid newb? Thanks in advance.